Assembly errors have great influence on assembly quality in robotic assembly systems. Error analysis is directed to the propagations and accumula-tions of various errors and their effect on assembly success.Using the ...Assembly errors have great influence on assembly quality in robotic assembly systems. Error analysis is directed to the propagations and accumula-tions of various errors and their effect on assembly success.Using the screw coordinates, assembly errors are represented as 'error twist', the extremely compact expression. According to the law of screw composition, relative position and orientation errors of mating parts are computed and the necessary condition of assembly success is concluded. A new simple method for measuring assembly errors is also proposed based on the transformation law of a screw.Because of the compact representation of error, the model presented for error analysis can be applied to various part- mating types and especially useful for error analysis of complexity assembly.展开更多
Reinforcement of TPNR （thermoplastic natural rubber） with cotton fibre spun was prepared by using hot compression moulding. The TPNR was prepared by mixing NR （natural rubber） with PE （polyethylene） using 2-roll...Reinforcement of TPNR （thermoplastic natural rubber） with cotton fibre spun was prepared by using hot compression moulding. The TPNR was prepared by mixing NR （natural rubber） with PE （polyethylene） using 2-roll mills before compressed on cotton fibre spun and vulcanized at 150℃. The mechanical properties and morphology of the membrane were investigated using DMTA （dynamic mechanical thermal analyzer） and SEM （scanning electron microscopy）, respectively. The membrane strength was increased from 10 MPa to 18 MPa after reinforced with cotton fibre spun as well as the increasing of dielectric constant. The membrane was immersed in xylene to remove PE phase before characterization of membrane properties.展开更多
基金This work is Supported by the National Science Foundation under Grant 863 -512 -9820-04.
文摘Assembly errors have great influence on assembly quality in robotic assembly systems. Error analysis is directed to the propagations and accumula-tions of various errors and their effect on assembly success.Using the screw coordinates, assembly errors are represented as 'error twist', the extremely compact expression. According to the law of screw composition, relative position and orientation errors of mating parts are computed and the necessary condition of assembly success is concluded. A new simple method for measuring assembly errors is also proposed based on the transformation law of a screw.Because of the compact representation of error, the model presented for error analysis can be applied to various part- mating types and especially useful for error analysis of complexity assembly.
文摘Reinforcement of TPNR （thermoplastic natural rubber） with cotton fibre spun was prepared by using hot compression moulding. The TPNR was prepared by mixing NR （natural rubber） with PE （polyethylene） using 2-roll mills before compressed on cotton fibre spun and vulcanized at 150℃. The mechanical properties and morphology of the membrane were investigated using DMTA （dynamic mechanical thermal analyzer） and SEM （scanning electron microscopy）, respectively. The membrane strength was increased from 10 MPa to 18 MPa after reinforced with cotton fibre spun as well as the increasing of dielectric constant. The membrane was immersed in xylene to remove PE phase before characterization of membrane properties.
